Arthur Shapiro’s Situationist Illusion

Arthur Shapiro has posted another of his remarkable illusions this week on his outstanding blog, Illusion Sciences.

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This illusion has special significance to us because, it is a “situationist illusion.” As Professor Shapiro explains:

One of my favorite places on the web is The Situationist, a blog that explores how the “situation” (or context) affects interpretation. The site has numerous examples of how objects, people, and events in one context are interpreted differently from the same objects, people, and events placed in another context.

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The visual display above presents an example of the effects of the visual “situation.” In one situation (vertical orientation for the disks), the viewer interprets the disks with reference to the background context (i.e., the two curtains). One disk looks like a shadow on the curtain, and the other looks like a spotlight. The disks are therefore interpreted as a dark spot and a lighter spot on the curtains. In another situation (horizontal orientation), the viewer is able to separate the disks from the context of the curtains and therefore will identify the disks as having the same shading.

To learn why the disks look different or similar to one another depending on whether they are oriented vertically or horizontally, or to look at more of Professor Shapiro’s award-winning illusions, click here.